1. Field of the Invention
The present invention relates generally to surgical instruments for use in orthopedic tools. In particular, the present invention relates to a connector for securing an orthopedic tool to a drive device.
2. Prior Art
Surgical tools for use in the cutting of bone and tissue are conventional in the art. Many of these tools are connected to a handle or motor, which is used to manipulate and drive the tool during a surgical procedure.
Generally, these tools are used to cut and shape bone as well as remove tissue in preparation for insertion of an orthopedic implant. As such, these procedures require that bone and/or tissue be precisely cut and/or removed to ensure proper positioning and fit of an orthopedic implant. Any unexpected movement of the surgical tool during use, such as handle slippage, unintentional rotation, or mechanical play, is not optimal as it could result in undesirable surgical outcomes.
Many prior art tool connectors are prone to these problems. For example, some prior art connectors are designed such that they contact a smooth outer diameter of the shaft of the tool. The contacting portion of a connector of such a prior art design could move along the tool shaft during use, resulting in unexpected slippage of the tool within its handle.
Additionally, some prior connector devices require that the locking mechanism be activated before insertion of the tool shaft. This limitation requires an additional step in connecting the tool to a handle during the surgical procedure. Activation of the locking mechanism may require assistance which may not be available when required. Furthermore, the orientation of such a connector activation mechanism may not be ideally positioned during the surgical procedure. For example, a button or lever mechanism may be oriented in a position that is difficult to reach or is not accessible. Unlike these prior art devices, a tool drive shaft is simply inserted and advanced into the connector of the present invention where it is locked into place. This locking feature of the connector of the present invention provides an efficient and secure means by which a tool is connected to a drive device, such as a handle or motor.
Therefore, for these reasons, it is desirable to provide a mechanical connector with an improved locking mechanism. A connector locking mechanism that offers a more secure, robust, easy to use, efficient connection between an orthopedic tool and drive device is provided by the present invention.
The connector of the present invention comprises a ball and a spring-loaded sleeve mechanism, which engages a groove that circumferentially extends around the drive shaft of a tool. The tool drive shaft is locked into place by a series of locking balls, which are forced into an annular groove of the drive shaft by the spring-loaded sleeve. The mechanism of the present invention is designed such that when in the locked position, forward and rearward movement of the tool drive shaft is prevented by an interference relationship of the balls captured between the spring-loaded sleeve and the annular groove of the tool drive shaft.
Additionally, the connector mechanism of the present invention accommodates drive shafts of differing size diameters. The spring-loaded sleeve, located within the mechanism, enables the balls to lock with shafts of differing diameters, both large and small. Also, the spring action of the sleeve mechanism of the present invention allows for the locking balls to contact drive shafts of different diameters. This enables an operator to robustly secure tool drive shafts with diameter tolerance variations. Furthermore, the design of the present connector mechanism does not require special tool shaft designs. Existing tool drive shafts can easily be inserted and locked into the connector of the present invention.
The features of the locking mechanism of the connector of the present invention address the shortcomings of prior locking connectors. The present connector provides a more reliable and selectively releasable connection between the surgical tool and its handle or motor, thereby reducing undesired mechanical movement such as mechanical play, slippage and/or unintentional rotation between the tool drive shaft and the handle or motor. These features and other benefits will be further discussed with respect to the locking connector of the present invention described herein.